Where
to Find
Placers

Placers can be found in
virtually any
area where gold occurs in hard rock (lode) deposits. The gold is
released
by weathering and stream or glacier action, carried by gravity and
hydraulic
action to some favorable point of deposition, and concentrated in the
process.
Usually the gold does not travel very far from the source, so knowledge
of the location of the lode deposits is useful. Gold also can be
associated
with copper and may form placers in the vicinity of copper deposits,
although
this occurs less frequently.

Geological events
such as uplift
and subsidence may cause prolonged and repeated cycles of erosion and
concentration,
and where these processes have taken placer deposits may be enriched.
Ancient
river channels and certain river bench deposits are examples of
gold-bearing
gravels that have been subjected to a number of such events, followed
by
at least partial concealment by other deposits, including volcanic
materials.
Residual placer deposits formed in the immediate vicinity of source
rocks
are usually not the most productive, although exceptions occur where
veins
supplying the gold were unusually rich. Reworking of gold-bearing
materials
by stream action leads to the concentrations necessary for
exploitation.
In desert areas deposits may result from sudden flooding and outwash of
intermittent streams.

As material gradually
washes off
the slopes and into streams, it becomes sorted or stratified, and gold
concentrates in so-called pay streaks with other heavy minerals, among
which magnetite (black, heavy, and magnetic) is almost invariably
present.
The gold may not be entirely liberated from the original rock but may
still
have the white-to-gray vein quartz or other rock material attached to
or
enclosing it. As gold moves downstream, it is gradually freed from the
accompanying rock and flattened by the incessant pounding of gravel.
Eventually
it will become flakes and tiny particles as the flattened pieces break
up.

Some gold is not readily
distinguishable
by the normal qualities of orange-yellow to light yellow metallic color
and high malleability, where it occurs in a combined form with another
element, such as tellurium. Upon weathering, such gold may be coated
with
a crust, such as iron oxide, and have a rusty appearance. This "rusty
gold,"
which resists amalgamation with mercury, may be overlooked or lost by
careless
handling in placer operations.

As mentioned before,
the richest
placers are not necessarily those occurring close to the source.Much
depends
on how the placer materials were reworked by natural forces. Streambed
placers are the most important kind of deposit for the small-scale
operator,
but the gravel terraces and benches above the streams and the ancient
river
channels (often concealed by later deposits) are potential sources of
gold.
Other types of placers include those in outwash areas of streams where
they enter other streams or lakes, those at the foot of mountainous
areas
or in regions where streams enter into broader valleys, or those along
the ocean front where beach deposits may form by the sorting action of
waves and tidal currents. In desert areas, placers may be present along
arroyos or gulches, or in outwash fans or cones below narrow canyons.

Because gold is
relatively heavy,
it tends to be found close to bedrock, unless intercepted by layers of
clay
or compacted silts, and it often works its way into cracks in the
bedrock
itself. Where the surface of the bedrock is highly irregular, the
distribution
of gold will be spotty, but a natural rifflelike surface favors
accumulation.
Gold will collect at the head or foot of a stream bar or on curves of
streams
where the current is slowed or where the stream gradient is reduced.
Pockets
behind boulders or other obstructions and even moss-covered sections of
banks can be places of deposition. Best results usually come from
materials
taken just above bedrock. The black sands that accumulate with gold are
an excellent indicator of where to look.

It should be kept in
mind that
each year a certain amount of gold is washed down and redeposited
during
the spring runoffs, so it can be productive to rework some deposits
periodically.
This applies chiefly to the near-surface materials such as those
deposited
on the stream bars or in sharp depressions in the channels. The
upstream
ends of stream bars are particularly good places for such deposits.
Where
high water has washed across the surface by the shortest route, as
across
the inside of a bend, enrichment often occurs.

A rifflelike surface
here will
enhance the possibility of gold concentration. In prospecting areas
with
a history of mining, try to find places where mechanized mining had to
stop because of an inability to follow and mine erratic portions of
rich
pay streaks without great dilution from nonpaying material. Smaller
scale
selective mining may still be practical here if a miner is diligent.

Problems
With
Water

The need for a good,
dependable,
and plentiful supply of water increases geometrically with the scale of
operation in placer mining. Panning gold requires very little water and
can be done in a small tub if necessary. At the other extreme, the
hydraulic
monitor, once in use, employed large flows of water under high
pressure,
and sluicing at a large operation could consume virtually all the water
that might be available. One thing the placer miner must keep in mind
is
the seasonal nature of stream flow. This affects both the supply of
water
and also the problems of pollution for downstream users

and damage to stream ecology.

Various means are used to
divert and
impound water. Channels, pipes, and flumes can beconstructed to conduct
water where it is wanted. If supply at a continuous flow is limited,
storage
must be provided, and placer operation is then restricted to periodic
activity
and depends on the capacity of the reservoir. A simple tank may make a
suitable reservoir for a small operation. Pumps are commonly used now
where
power is cheap enough, and the recirculation enables use of a smaller
supply
of water.

Basic
Equipment

Among the essential
implements
needed for prospecting are a pick; a long-handled, round-pointed
shovel;
and a gold pan, preferably a 30-40cm diameter pan which can usually be
purchased at hardware stores in gold-mining areas. A small prospector's
pick is also useful, and a magnet and a small amount of mercury should
be carried to separate the gold from black sand after panning.Specialty
stores and manufacturers can provide the more elaborate equipment, such
as skindiving gear, ready-built sluices, and mechanical gold separation
devices, if desired.

In some cases, a
bucket or wheelbarrow
may be needed to transport materials to the washing site, and in
addition,
a heavy .25-.75cm -mesh screen is handy to separate out coarse
materials.
A small screen cut to nest in the upper part of a gold pan can be
useful
for the same purpose in panning. A gold pan the same size as the one
used
for panning will make a most efficient nesting screen if a close
pattern
of holes is drilled in the bottom. Holes usually should be .24-.75cm in
diameter, depending on the average size of the material being sampled.
Distance between holes should be about the same as the diameter of the
holes. In some areas these pans can be purchased readymade. For
weighing
gold, a small balance scale graduated in milligrams may be desirable. A
compact, folding type of balance is available for this purpose.

A compass will be
needed for establishing
claim lines and for finding your way out of the woods if lost. Adequate
maps should be carried. A hand magnifying lens is helpful in
identifying
minerals. Bags may be needed to carry out samples; plastic bags are the
best because samples may be damp. A rocker may be transported to the
site
either assembled or in a knocked-down condition. If mining is planned,
lumber and other materials to build a sluice may be carried to the
site.
(See construction details under respective headings.) More elaborate
equipment
such as pumps, pipes, hoses, and light plants might be taken in by pack
animals if desired.

Personal gear
includes a good
pair of boots, sturdy clothing, weatherproof gear, sleeping bag, tent,
and such other things as one might want for comfort and sanitation. A
foam
pad or air mattress adds comfort to sleeping. A length of rope is
useful
for many purposes around camp, from raising the food out of reach of
animals
to extracting a car from a mudhole. For hiking, all necessary equipment
for the period away from camp should fit into a manageable backpack of
some kind.

An ax, a flashlight,
a knife,
and matches are almost indispensable. (Fires in the National Forest
should
be made only in designated areas or after consulting the local forest
ranger.)
A water bucket is often required, and a good crosscut saw will be found
useful. Guns and fishing equipment can be taken to supplement the food
supply and to provide some additional recreation. Guns are seldom
necessary
for protection from animals. A canteen with a 2-quart or larger
capacity
is advisable in many areas, depending on dryness of the climate. You
will
need water-purification tablets where streams are contaminated, whether
by grazing stock or for other reasons. A miner's lamp, which consumes
calcium
carbide, is sold at some hardware stores and can be used for a
serviceable
light, although most people when away from electricity prefer gasoline
or propane lamps. A carbide lamp will also be useful for any
underground
work. The special miner's safety lamp is recommended wherever air may
be
bad. Stoves that burn gasoline or pressurized gas are in wide use in
camping
and even gas refrigerators may be taken along "to cool the beer." (For
low-budget operations, a swift-running stream will serve this same
purpose
well.) For any length of time in the field, an oven for baking is a
valuable
amenity. A reflector oven for use next to a campfire can be made of
light
sheet metal and will give excellent results, also serving as a place to
keep food warm.

Supplies

Freeze-dried foods
are generally
good and easy to carry and prepare, although somewhat more expensive
than
most other foods. For estimating pack weights, about 2 pounds of
dehydrated
and freeze-dried foods is needed per person per day. Canned foods
should
be avoided when backpacking because of their weight, but they are
otherwise
satisfactory. Disposal of empty containers should be done with
consideration
to others who may follow and wish an uncluttered landscape; burial is
usually
recommended.

Suggested food
supplies for a
prospector's camp include the following: bacon, beans, cheese, salt,
baking
powder and soda, coffee, tea, onions, potatoes, fruits, corn. peas.
raisins,
rice, flour, crackers, cereals, butter or margarine, powdered milk,
eggs,
pancake and waffle mix, sugar, syrup, and fresh meat and vegetables as
practicable. Many other items can be added to the list, but these are
most
of the basics. Utensils should include a variety of dishes, silverware,
a sharp knife, spatula, can opener, frying pan, coffee pot, and several
different sizes of pots and pans. Towels, both paper and cloth, soap,
scouring
pads, and metal or plastic tubs or basins will be needed for cleaning
up.

Extra clothing should
be included
in your supplies for warmth and for changes. Mosquito netting may be a
virtual necessity in some areas, and adequate amounts of a good insect
repellent should be packed.

Wild animals are
seldom dangerous
except when provoked, but smaller ones such as packrats can inflict
considerable
damage on camp gear and foodstuffs. Poisonous snakes, spiders, ticks,
scorpions,
and the like should be treated with traditional caution; their presence
should be anticipated in most areas. Learn to identify and avoid poison
oak and poison ivy' Knowledge of first aid is essential for dealing
with
emergencies that might arise on an outing, and a study or review of the
subject should be included in any preparations.

Some of the personal
hazards faced
in the out-of-doors include twisted ankles, lacerations from falling in
brush, falls from slippery rocks or crude bridges when crossing
streams,
breaking through floors in old building ruins, and falls or cave-ins in
old mine workings. Beware of bad air in any old workings' Danger of
drowning
or being attacked by a crocodile is always present when working around
the deeper streams or pools when placer mining.

Many types of first
aid kits and
equipment are on the market. The choice of kit is one of size and
variety
of content. A snakebite kit is usually a separate accessory and should
be carried, even though it is rarely put to use. Disinfectants,
aspirin,
fungicides, bandages, and similar items should be included. For areas
of
considerable sunshine, tanning lotion, sunglasses, and a hat are
needed,
and salt tablets should be taken as designated to prevent heat
prostration.
Wearing a safety hardhat and safety glasses may be advisable at times.

Panning
for Gold

The standard gold pan
is made
of stiff sheet iron and is 35cmin diameter at the top and 5-6cm deep.
The
rim is flared outward at an angle of about 50 degrees from the
vertical.
Smaller pans are used for testing, and it is advisable for most panners
to use either a 30-40cm size for handling ease. Probably the 1.25cm is
the most widely available. Frying pans or other cooking utensils may
also
be used for washing out gold but are less effective. Before any kind of
container is used for panning it should be cleaned thoroughly and all
grease
should be burned out. New pans generally are greasy and should be
heated
over a fire until this coating is gone. Even a rusty pan, if clean, can
be used satisfactorily. In fact, the roughness due to the pitting of
the
rust may assist in holding back the gold.

There are different
techniques
and subtle variations in the art of panning--experience teaches which
is
best. Those with wide experience and much practice can recover the most
gold with the least effort.It is sometimes said that good panning
technique
lies in the action of the wrists. After much practice the good panner
should
be able to save even the very fine gold that may be nearly but not
quite
free from the black sands.

The pan usually is
filled level
with the top, or slightly rounded, depending somewhat upon the nature
of
the material being washed and the personal preference of the panner. It
is then submerged in water. Still water 20-30cm deep is best. While
under
water the contents of the pan are kneaded with both hands until all
clay
is dispersed and the lumps of dirt are thoroughly broken. The stones
and
pebbles are picked out after the fines are washed off. Then the pan is
held flat and shaken under water to permit the gold to settle to the
bottom.
The pan is then tilted and raised quickly -- still under water -- so
that
a swirling motion is imparted and some of the lighter topmaterial is
washed
off. This operation is repeated, occasionally shaking the pan under
water
or with water in it until only the gold and heavy minerals are left.
With
proper manipulation, this material concentrates at the edge of the
bottom
of the pan. Care must be taken that none of the gold climbs to the lip
of the pan or gets on top of the dirt.

Nuggets and coarse
colors of gold
can now be picked out readily with a tweezer or with the point of a
knife.
Cleaning the black sand from the finer gold is more difficult, but can
be carried nearly or entirely to completion by careful swirling of the
contents as described above, always watching to see that none of the
colors
are climbing toward the lip. This part of the operation usually is done
over another pan or in a tub so that if any gold is lost it can be
recovered
by repanning.

The concentrates should be
dried, and
the black sands (composed largely of magnetite) can then be removed by
a magnet or by gently blowing them on a smooth flat surface. If there
is
an excessive quantity of black sand, the gold usually is amalgamated by
putting a portion of a teaspoonful of mercury in the pan. In sampling
work,
extra care should be taken to see that no fine colors are lost. When
mining,
however, additional time needed to insure that all colors are saved
probably
is not justified because the value they add is so small.

A word should be said
here about
other minerals that you may see in your gold pan. Pyrite ("fool's
gold,"
an iron sulfide) and mica are often mistaken for gold by the novice.
Pyrite,
which is usually a brassy yellow to white color, will shatter when
struck
with a hammer and becomes a black powder when finely ground. Mica,
which
may have a bright, bronzy appearance, is distinguished by its light
weight
and flat, platy cleavage. Both minerals are common in gold areas. Other
minerals that will collect with the gold and black sands because of
high
specific gravity include ilmenite (iron-titanium oxide), hematite
(nonmagnetic
iron oxide), marcasite (an iron sulfide), rutile (titanium oxide),
scheelite
(calcium tungstate), wolframite (iron, manganese tungstate), tourmaline
(boron and aluminum silicate), zircon (zirconium silicate), chromite
(iron
and chromium oxides), and cinnabar (mercury sulfide). If present in
sufficient
quantity, these latter minerals may have some economic significance,
although
efforts to recover them as byproducts are seldom worthwhile.

Native platinum, elemental
mercury,
lead shot, and similar materials are also occasionally found in the
pan.

Evaluation:
Should You Invest And Mine?

This question becomes
more difficult
to answer as the size of the planned operation increases.Estimation of
the amount of gold recoverable and the overall costs of investment and
mining is no simple matter and calls for highly experienced engineering
skills for any moderate- to large-scale project. Elaborate procedures
of
sampling and evaluation cannot be followed by the small-scale operator
because of the cost. Thus, his decisions must be based on a variety of
factors, not the least of which is intuition. Needless to say, many
mistakes
have been made, with much resultant waste of money and effort. Do not
let
what started out as a recreational activity become your master
insteadof
your servant.

Sampling
Techniques

Many methods of
sampling are possible,
including the simple panning of gravel from surface exposures, churn
drilling,
test pitting and trenching, shaft sinking, and drifting. As an aid in
tracing
possible gold-bearing channels, geophysical techniques have been
employed
with some success, but proper use of the typical instruments involved
is
generally reserved to experts. Moreover, interpretation of results is
seldom
adequate to provide any quantitative estimates, although the
information
gained can be useful in planning an exploration program.

Panning and rocking
(described
later) are the basic means of determining the recoverable gold content
of placer materials. A fire assay, sometimes made on a concentrate,
provides
a relatively complete estimate of the gold content of the material, but
a poor estimate of how much gold can actually be extracted by
conventional
washing methods. Thus, placer gold is seldom assayed, exceptto
determine
its fineness (measure of gold purity). In estimating the value of gold
in the pan after washing a quantity of gravel, the technique of
counting
nuggets and "colors" is normally followed. Generally, pieces worth more
than 50 or 100 cents are considered as nuggets; smaller particles are
colors.
When skill is developed in estimating the various sizes of particles, a
good degree of consistency can be achieved in the results.

Where samples can be
obtained
across a section of the bank exposed along a creek, it is good practice
to cut a vertical groove or channel of fairly consistent width and
depth.
The sample may be cut from top to bottom, or in segments comprising
several
different samples if the bank shows distinct changes in materials. Bars
may be sampled by digging a vertical hole, clear to bedrock if
possible,
and panning the product. For surface mining of "skim bars," sampling
consists
of simply taking a panful from a favorable point and visually
estimating
the amount of similar material in the vicinity. Clearly, there is not
much
accuracy in any of these methods, but the deposition of gold in such
locations
is bound to be erratic anyway. More representative sampling is usually
possible in the larger deposits where deposition and size of gold
particles
is more uniform or consistent.

For the small-scale
miner, sampling
will usually be limited to taking a panful here and there and possibly
running a larger sample through a rocker or sluice if panning discloses
any gold. If colors are found, a record should be made of the number
and
estimated size of colors per pan and the approximate location. The
sampling
then progresses until one is assured the prospects are good enough to
warrant
a mining operation of some sort. A scale of sizes and approximate
values
of colors based on pure gold at $350 an ounce is as follows:

It is common to
report panning
results in cents per pan. So, assuming you have determined that a "pan
factor" of about 400 pans per cubic metre (bank measure) for the 30cm
pan
is a suitable figure, multiplying the cents-per-pan figure by 400 gives
the estimated value per cubic metre.

Another means of
estimating is
to rank the colors into three groups, as follows:

Number l: colors
weighing over
4 milligrams

Number 2: colors
weighing between
1 and 4 milligrams

Number 3: colors weighing less
than
1 milligram

(Note: 31,103 milligrams equals
1 troy
ounce.)

Scales will be needed
to check
the weights until the eye can judge the sizes properly. It is
recommended
that particles over 10 milligrams be weighed individually. A rough
measure
of value is one-tenth of a cent per milligram.

Thus, the value in a
pan can be
calculated using your visual count and tally of the number of colors of
each rank. After sufficient practice, good estimates will come easily.
Thickness has a great bearing on weight: For instance, some gold might
look large, but actually be flat, flaky, and hence very light.

Determining the
overall value
of a deposit with any accuracy calls for a knowledge of accepted
practices
and mathematical procedures for weighting the values and sample
intervals.
It is important also to understand the statistical principles of
variation
and distribution, which are beyond the scope of this report. Generally,
the practical prospector will take a few measurements,make some crude
calculations
using his panning results, and decide to stay or move on.

How
To Go About
Mining

When a site where
gold is known
to occur has been found, and after it has been sampled and judged
worthy
of further effort, the ownership status should be checked to assure
that
the ground is open for claiming. Then, after staking adequate claims
(or
arranging to lease if the ground is not open to claim), you are ready
to
consider mining. Whether mining permits are required should be
investigated,
because placer operations of any size may drastically change the local
water quality. A simple operation may have virtually no effect on a
stream
or surroundings, but when materials amounting to more than a few cubic
metres a day are handled, the possible effects begin to become
significant.

Choosing
a Recovery
Method

Among the simpler
hand methods
of recovering gold are the gold pan, the rocker, the dip-box, thelong
tom,
and the sluice. Panning has been described in a previous section,
entitled
"How to Look for Placers," and will only be discussed briefly here. The
pan is generally too slow to be effective for anything more than
prospecting.
The rocker is a time-honored device of the small-scale miner with
limited
means. The dip-box and long tom might be considered more like
simplified
sluicing methods than distinct methods in themselves. As a method, the
long tom has never been very popular but is described here for its
possible
historical interest. Other methods used in specific circumstances would
include the surf washer, the dry washer, and skindiving.

The simpler methods
all normally
involve hand-mining operations (shoveling and/or picking of the
gold-bearing
materials). Limited mechanization is sometimes practical for moving and
washing gravels in even the smallest operation, and this possibility
should
not be overlooked. Even motorized devices for panning are marketed by
several
manufacturers. Pumps and small excavators can often be adapted to the
small
mining operation by the enterprising miner.

The more complex
methods, such
as ground sluicing, hydraulicking, drift mining, excavation using
powered
equipment, and dredging, require considerable investment, knowledge,
and
experience; a full discussion of these methods is beyond the scope of
this
report.

The choice of method
depends primarily
on the scale of operation and the availability of water. These and
other
characteristics of the different methods are discussed below.

Gold
Pan

Panning is the
hardest way to
wash gold from placer gravels, but it is an inexpensive and completely
mobile method. A person can dig with a pick and shovel much faster than
he can pan the material dug, so it pays to treat only the highest grade
products by panning once one has settled down to mining.

An experienced person can wash
about
10 large pans per hour, the equivalent of approximately 1/2 to 1 cubic
metre of gravel per day, depending on how clean the gravel is. A
level-full,
standard 30cm pan might contain roughly 22 pounds of dry bank gravel;
there
are approximately 150 to 180 pans per cubic metre of gravel. More than
twice as many 30cm pans would be required per cubic metre. The top dirt
or cover is usually cast aside and the few centimteres of material
directly
above bedrock and the material scraped from crevices is panned. Places
to look and the proper panning technique have been covered in earlier
sections.

Rocker

At least twice as
much gravel
can be worked per day with the rocker as with the pan. The rocker or
cradle,
as it is sometimes called, must be manipulated carefully to prevent
loss
of fine gold. With the rocker, the manual labor of washing is less
strenuous,
but whether panning or rocking, the same method is used for excavating
the gravel.

The rocker, like the pan, is
used extensively
in small-scale placer work, in sampling, and for washing sluice
concentrates
and material cleaned by hand from bedrock in other placer operations.
One
to three cubic metres, bank measure, can be dug and washed in a rocker
per man-shift, depending upon the distance the gravel or water has to
be
carried, the character of the gravel, and the size of the rocker.
Rockers
are usually homemade and display a variety of designs. A favorite
design
consists essentially of a combination washing box and screen, a canvas
or carpet apron under the screen, a short sluice with two or more
riffles,
and rockers under the sluice. The bottom of the washing box consists of
sheet metal with holes about 1.25cm in diameter punched in it, or a
1.25cm-mesh
screen can be used. Dimensions shown are satisfactory but variations
are
possible. The bottom of the rocker should be made of a single wide,
smooth
board, which will greatly facilitate cleanups. The materials for
building
a rocker cost only a few dollars, depending mainly upon the source of
lumber.

After being dampened,
the gravel
is placed in the box, one or two shovelfuls at a time. Water is then
poured
on the gravel while the rocker is swayed back and forth. The water
usually
is dipped up in a simple long-handled dipper made by nailing a tin can
to the end of a stick. A small stream from a pipe or hose may be used
if
available. The gravel is washed clean in the box, and the oversize
material
is inspected for nuggets, then dumped out. The undersize material goes
over the apron, where most of the gold is caught. Care should be taken
that not too much water is poured on at one time, as some of the gold
may
be flushed out. The riffles stop any gold that gets over the apron. In
regular mining work, the rocker is cleaned up after every 2 to 3 hours,
or oftener when rich ground is worked and gold begins to show on the
apron
or in the riffles. In cleaning up after a run, water is poured through
while the washer is gently rocked, and the top surface sand and dirt
are
washed away.

Then the apron is
dumped into
a pan. The material back of the riffles in the sluice is taken up by a
flat scoop, placed at the head of the sluice, and washed down gently
once
or twice with clear water. The gold remains behind on the boards, from
which it is scraped up and put into the pan with the concentrate from
the
apron. The few colors left in the sluice will be caught with the next
run.
The concentrate is cleaned in the pan.

Skillful manipulation
of the rocker
and a careful cleanup permit recovery of nearly all the gold. Violent
rocking
should be avoided, so that gold will not splash out of the apron or
over
the riffles.The sand behind the riffles should be stirred occasionally,
if it shows a tendency to pack hard, to prevent loss of gold. If the
gravel
is very clayey it may be necessary to soak it for some hours in a tub
of
water before rocking it.

Where water is
scarce, two small
reservoirs are constructed, one in front and the other to the rear of
the
rocker. The reservoir at the front serves as a settling basin. The
overflow
drains back to the one at the rear, and the water is used over again.

The capacity of
rockers may be
increased by using power drives. Such a device might be rocked by an
eccentric
arm at the rate of approximately forty 15cm strokes per minute. The
capacity
of the typical machine with two men working is 1 cubic metre per hour.
Where gravel is free from clay, the capacity may be as great as 3 cubic
metres per hour. The cost of the mechanized rocker and a secondhand
engine
for driving it is estimated at $400.

Dip-Box

The dip-box is useful
where water
is scarce and where an ordinary sluice cannot be used because of the
terrain.
It is portable and will handle about the same quantity of material as
the
rocker. Construction is relatively simple. The box has a bottom of 2.5
by 30cm lumber to which are nailed 2.5 by 30 cm sides and an end that
serves
as the back or head. At the other end is nailed a piece approximately
2.5cm
high. The bottom of the box is covered with burlap, canvas, or thin
carpet
to catch the gold, and over this, beginning 30cm below the back end of
the box, is laid a 30 by 90cm strip of heavy wire screen of about 0.5cm
mesh. The fabric and screen are held in place by cleats along the sides
of the box. Overall length may be 2 to 3 metres, although nearly all
gold
will probably collect in the first 1metre. The box is placed so the
back
is about waist high; the other end is 15 to 30 cm lower. Material is
simply
dumped or shoveled into the upper end and washed by pouring water over
it from a dipper, bucket, hose, or pipe until it passes through the
box.
The water should not be poured so hard that it washes the gold away.
Larger
stones (after being washed) are thrown out by hand, or a screenbox can
be added to separate them. Riffles may be added to the lower section of
the box if it is believed gold is being lost.

Long
Tom

A long tom usually
has a greater
capacity than a rocker and does not require the labor of rocking. It
consists
essentially of a short receiving launder, an open washing box 2 to 4
metres
long with the lower end a perforated plate or a screen set at an angle,
and a short sluice with riffles . The component boxes are set on slopes
ranging from 5-7cm per 30cm. The drop between boxes aids in breaking up
lumps of clay and freeing the contained gold.

A good supply of
running water
is required to operate a long tom successfully. The water is introduced
into the receiving box with the gravel, and both pass into the washing
box.

The sand and water
pass through
the screen's 1.25cm openings and into the sluice. The oversize material
is forked out. The gold is caught by the riffles. The riffle
concentrates
are removed and cleaned in a pan. Quicksilver may be used in the
riffles
if the gravel contains much fine gold.

The quantity of
gravel that can
be treated per day will vary with the nature of the gravel, the water
supply,
and the number of men employed to shovel stones into the tom and then
fork
them out. For example, two men, one shoveling into the tom and one
working
on it, might wash 6 cubic metres of ordinary gravel, or 3 to 4 cubic m
of cemented gravel, in 10 hours.

A tom may be operated
by four
men--two shoveling in, one forking out stones, and one shoveling fine
tailings
away. Where running water and a grade are available, a simple sluice is
generally as effective as the long tom and requires less labor.

Sluice

A sluice is generally
defined
as an artificial channel through which flows controlled amounts of
water.
In gold placering, the sluice includes sluiceboxes which collect the
gold
by means of various configurations of riffles, corrugations, mats,
expanded
metal, or the like, which trap the heavier particles while allowing the
waste to continue through.

An important part of
any sluicing
operation is its water supply, and where water is not plentiful, pumps,
pipelines, or even dams with special headgates may be required.

Small-scale sluicing
by hand methods
has been called quite appropriately shoveling-into-boxes. In contrast,
in ground sluicing, usually a more efficient operation, most of the
excavation
is accomplished by the action of water flowing openly over the
materials
to be mined. In either case, the materials pass through a sluice, where
gold is collected behind riffles. A variation of the sluicing
technique,
where water is stored and released against or across the materials
intermittently,
is called booming.

The sluicebox in its
simplest
form might be a 4m-long plank of 2.5-5cm pine lumber, to which sides
about
25-30cm high are nailed, with braces secured at several places across
the
top. Larger sluices can be made with battens to cover joints between
boards
where gold might slip out, and with braces built around the outsides of
the box for greater rigidity. To provide for a series of boxes, the
ends
should be beveled or the units tapered so that one will slip into the
other
in descending order and form a tight joint. Four to eight such boxes in
series would be a typical installation. Two men hand-shoveling into
sluiceboxes
can wash 5 to 10 times as much gravel as could be put through a rocker
in a day. The slope of the sluice and the supply of water must be
adjusted
so that the gravel, including larger cobbles, will keep moving through
the boxes and on out. Slopes of 10-15cm per 30cm box are normal, but if
water is in short supply the slope may be increased. Trestles are
necessary
to support the boxes over excavated ground, gulleys, or swales.

Inside the boxes,
various kinds
of riffles may be employed, depending upon availability of material and
personal preference. The riffles, which go on the bottom, are usually
set
crosswise in the box, but they can also be effective when placed
lengthwise,
the concentrates settling between them. They may be of wood, or of
strap
or angle iron, or a combination of the two. Straight, round poles or a
pattern of square blocks or stones can serve for riffles. Rubber or
plastic
strips have even been used. Durability is important for prolonged
operations,
so wood may be armored with metal. Expanded metal, heavy wire screen,
or
cocoa mats make good riffles for collecting fine gold.

A common height for
riffles is
5-7cm ; they may be placed from one-half to several cm apart. Fastening
the riffles to a rack, which is then wedged into place in the box,
permits
their removal. A tapered shape on the cross riffle, with the thinnest
edge
to the bottom, tends to create an eddying action that is favorable for
concentration. Another way to achieve this eddying action is to cant
the
riffle or even just the top of the riffle. Burlap or blanket material
is
commonly placed under the riffles to help in collecting fine gold.
Mercury
may be added to some sections of the sluice if there is much fine gold,
but care must be taken to prevent escape of the mercury.

Sluice cleanups should be made at fairly
regular intervals. After running clear water until the sluice is free
of
gravel, riffles are removed in sections starting at the upper end. With
a thin stream of water, the lighter of the remaining material is washed
to the sections below. The gold, heavy sands, and amalgam, if mercury
has
been used, are scraped up and placed in buckets. This mixture then can
be panned or cleaned up in a rocker to obtain a final concentrate or
amalgam.

Feeding the Sluice

It is common in a
small operation,
when feeding the sluice, to place a heavy screen or closely spaced bars
of some sort across the section where the gravels enter, to eliminate
the
larger particles, which are probably barren anyway. The screen or bars
(a "grizzly") should be sloped so the oversize material rolls off to
the
side. The size of mesh or spacing will depend upon the gradation of
feed,
butwould generally be in the range of 0.5-2.5cm, with 0.5cm being a
common
size. In larger operations a rotating screen, or trommel, might be
used.
In a ground sluicing operation, possibly all materials would be run
through
the sluiceboxes. Provisions must be made for removing the oversize
material,
and, if required, stacking it away from the work area.

If the gravel
contains much clay
it may be desirable to use a puddling box at the head of the string of
sluiceboxes. This may be any convenient size--for instance, 1 metre
wide
by 2 metres long, with 10 to 15cm sides. The clayey material is
shoveled
into this box and broken up with a hoe or rake before being allowed to
pass into the sluice. The importance of this step is that if allowed
through
the sluice, the unbroken clay lumps may pick up and carry away gold
particles
already deposited.

Usually, the
shoveling-in method
proceeds as follows: After the boxes are set, shoveling begins at an
advantageous
point. Experienced miners work out the ground in regular cuts and in an
orderly fashion. Enough faces are provided so that shovelers will not
interfere
with one another. Provision is made to keep bedrock drained, and
boulders
and stumps are moved a minimum number of times. Cuts are taken of such
a width and length that shoveling is made as easy as possible. The
boxes
are kept as low as possible so a minimum lift of gravel is necessary.
At
the same time an adequate slope must be maintained for the gravel to
run
through the boxes under the limitations of the available water.
Allowance
for dump room must also be provided at the tail end of the sluice.
Leaks
in the sluice are stopped promptly, and shoveling is done in such a
manner
that the sluice does not become clogged nor does water splash out
(Water
in the pit hampers shoveling.)

All material of a size that will run through
the sluice is shoveled in, and the oversize material is thrown to one
side.
Boulders from the first cut should be stacked outside the pit, on
barren
ground if possible. The width of a cut is usually limited to the
distance
a man can shovel in one operation.

When shoveling from more than a
couple
of metres away, it is best to set boards above and on the opposite side
of the box; this increases the efficiency of the shovelers. The
greatest
height a man can shovel into a box is 2.5 to 3 metres, and above 2
metres
the efficiency of the shoveler is markedly reduced. If the gravel is
over
1 to 1.25 metres deep, it usually is excavated in benches to facilitate
digging and to permit the upper layers to be raised a minimum shoveling
height. Where the gravel is shallow, wheelbarrows may be used. Another
way is to shovel the gravel onto a conveyor belt that discharges into a
trommel, discarding the oversize material and running the undersize
material
through the sluice. Where two or more persons are working in the same
cut,
the height of succeeding benches is governed by the character of the
material
being dug and the distance the gravel has to be lifted.

The sluice may be
maintained on
the surface of unworked ground or supported on bents on the opposite
side
of the cut. After the first cut the boulders are thrown onto the
cleaned-up
bedrock. Where cuts are run on both sides of the sluice, the boxes are
supported on bents as the ground underneath them is dug out. At other
places
the boxes may be set on bedrock and the dirt may be shoveled into the
head
of the sluice from short transverse cuts at the upper end of the pit.
Work
usually begins at the lower end of a deposit so that bedrock may be
kept
drained, and then proceeds across the deposit by regular cuts. The
length
and order of the cuts will depend upon local conditions. As heavy sands
and gravel build up deposits between the riffles in the sluice, it may
be necessary to stir these up to prevent packing and the consequent
override
of gold particles. A tined implement such as a pitchfork is often
convenient
for this. Larger stones that lodge in the sluiceway may be similarly
removed.

Supplying Water

The quantity of water
available
will influence the scale of operations and the size of sluice used. A
minimum
flow of 30-40cm (about 800L per minute) is required for a 30-cm-wide
sluicebox
with a steep grade. Smaller flows than this can be utilized by storing
the water in some kind of reservoir and using the supply
intermittently.
A common practice followed where the quantity of water is limited is to
use a grizzly or screen over the sluice to eliminate oversize material
and thus increase the duty of the water. Reduction in the amount of
material
to be treated by first running it through a trommel to wash and screen
out the coarse size is another effective way to lower the water
requirements.

Water usually is
conducted via
ditch to the sluice. However, if the ground is rich enough it may be
practicable
to pump water for the sluice. The feasibility of obtaining a gravity
flow
should first be investigated, as the expense of pumping may be more
than
the cost of a long ditch, when the cost is distributed over the
metreage
of gravel moved. A suitable number of sluiceboxes or some other removal
system may be used to transport the tailings to a dumping ground away
from
the working area. A tailings or settling pond may be required to
maintain
downstream water quality.

Ground sluicing utilizes the
cascading
effect of water to break down the gravel; hence, the requirements for
water
are much greater. The chief application of ground sluicing is to
streambed
deposits. Pipelines, flumes, or ditches would be necessary if ground
sluicing
were applied to gravels higher up on banks or terraces, and the larger
scale hydraulic methods would then become more favorable. If booming is
to be done, a dam and reservoir are needed. The dam is usually equipped
with a gate mechanism that permits either automatic or manual control
and
quick release of the impounded water for maximum washing effect. The
water
may be passed over the upper face of a gravel bank or diverted against
the bottom in order to undercut and carry away the gravel as the face
of
the bank breaks down. All materials are channeled toward the sluice.

The natural flow of a stream
can be
used by diverting the current with boards or simply with piled
boulders.
"Shears" can be constructed of 2.5 or 4cm-thick boards 4 metres long
nailed
to pairs of tripods so that the boards slope back from the water flow
at
an angle of about 60 degrees. The tripods are built in such a way that
boulders can be piled inside the base to hold them in place. A row of
these
shears may be used to divert the force of the water against a bank, or
two rows may be used to form a flume.

The seasonal nature of stream
flow in
different areas must be kept in mind when planning any placer
operation.
State and Federal agencies can provide information on stream runoff for
many of the more important streams, information which will indicate the
limitations in water supply that might be expected due to seasonal
changes.

Additional Methods Sometimes Used

The methods described
below, particularly
the surf washer, are limited in application, but interest in them
revives
from time to time, so they are included here. Many kinds of dry washers
have been developed, some very elaborate. Most dry-washing operations
have
a short lifespan, owing to the erratic character if the deposits.
Skindiving
for gold is not new, but development of better diving equipment in
recent
years has stimulated interest in the method, although restricted in
practice
to a few select stream areas. Shaft and drift mining are also among
methods
used in extracting placer gold gravels, but because techniques are more
related to other types of mining, discussion is not included in this
report.

Dry
Washer (for
Desert Areas)

Dry washers have been
used for
many years in the Southwestern United States, where water is scarce,
and
especially in New Mexico where several million dollars in gold has been
produced during the last century by dry washing. The Cerrillos, Golden,
and Hillsboro districts are among those having produced gold by dry
washing.
In years when other employment is scarce such production may take place
widely. In the 1930's a considerable number of men also used dry
washers
in Nevada, southern California, and Arizona. If gravel is to be treated
successfully by dry washing, it must be completely dry and
disintegrated.
For instance, after rainstorms, operations must be stopped until the
ground
dries out again. Even in very dry climates the gravel is slightly damp
below the surface, and must be dried before it can be treated in a dry
washer. Spreading the material to sun-dry or putting it through dryers
adds to the cost of mining. In small-scale work, however, the gravel
will
dry out about as fast as it can be treated.

Dry washers are usually run by
hand
and have about the same capacity as rockers of corresponding size, but
the work of operating the dry washer is much harder. The workers select
the material they are to treat with regard to both dryness and probable
gold content. It is difficult to do this on a large scale with hired
labour.
Plants with mechanical excavators and complex power-driven dry-washing
machinery have been tried, but in the United States, at least,
virtually
all were commercial failures, primarily because the gravel was dug
faster
than the sun could dry it out. Also, in large-scale work, particularly
with mechanical excavation, the cost of sizing the material is quite
great.
Clay and cemented gravel introduce even further difficulties.

When the gold-bearing material
is completely
dry and disintegrated, panning tests of the tailings should show that a
good saving can be made, except perhaps with extremely fine or flaky
gold.
Completely disintegrated material, however, is seldom obtained. The
tops
of clay streaks in the gravel are likely to be richer in gold than the
gravel itself. Clay or cemented gravel seldom can be broken up
sufficiently
by hand to free all the gold without the use of some form of
pulverizer.
In a dry washer all gold included in a lump of waste passes out of the
machine. As water usually will break up all the gravel and separate the
gold from the other material, a better saving usually can be effected
with
the rocker or sluiceboxes than with a dry washer.

Basically, the dry washer
separates
gold from sand by pulsations of air through a porous medium. The
screened
gravel passes down an inclined riffle box with cross riffles. The
bottom
of the box consists of canvas or some other fabric. Under the riffle
box
is a bellows, by which air in short, strong puffs is blown through the
canvas. This gives a combined shaking and classifying action to the
material.
The gold gravitates to the canvas and is held by the riffles, while the
waste passes out of the machine.

The gravel is shoveled into a
box holding
a few shovelfuls at the head of the washer, from which it runs by
gravity
through the machine. A screen with about 1.25cm openings is used over
the
box. All stones over about 2.5cm in diameter generally are discarded in
mining. A dry washer usually is run by a small petrol engine which
saves
the labor of one man. The capacity of such machines is considerably
greater
than that of hand-operated ones. For instance, one man working alone
must
fill the box, then turn a crank which runs the bellows until the gravel
runs through. The process is then repeated. With two men working, one
shovels
and the other turns the crank. One man can treat 1/2 to 1 cubic m per
day
with a hand-operated washer, where the gravel lies close to the
machine.

When cleaning up, the
material
behind the riffles usually is dumped into a pan and washed out in
water.
If water is very scarce, the accumulated material from the riffles may
be run through the machine a second time and then further cleaned by
blowing
away the lighter grains of sand in a pan.

Dry washers are usually
handmade and
have been built in a large number of designs and sizes. The bellows of
the machine is made of 36-ounce duck and the bottom of the riffle box
of
8-ounce, single-weave canvas.

In contrast to the
single-weave
canvas, silk or rayon permits a good extraction of gold, but too much
dust
goes through into the bellows. Heavier canvas is too tight for good
separation.
Copper-wire fly screen is used under the canvas. The riffle box is 30cm
wide and 1.1m long and contains six riffles. The slope of the riffle
box
is 30cm to the metre. (Hand-operated machines are usually much smaller
and the riffle box is set at a steeper angle than with powered
machines.)
The gravel and sand are shoveled onto a screen with 0.5cm openings at
the
top of the washer. The bellows is operated at 250 pulsations per
minute;
the stroke is 8cm. The capacity of the machine is about 4/5 metres per
hour, which probably would correspond to 1-1/2 or 2 cubic metres, bank
measure. (The plus 2.5cm material was previously discarded.)

In cleaning up after
treating
approximately 1 cubic metre in the washer, the riffle box is lifted out
and turned over on a large, flat surface, such as a baking tin. The
concentrate
from the upper three riffles is first panned, and the gold is removed.
Usually both the coarse and the fine gold can be saved here. The lower
riffles may contain a few colors, but nearly all the gold is normally
caught
in the upper riffles.

Few sea-beach-type
placer gold
deposits have been mined successfully. The most important producers
have
been in the vicinity of Nome, Alaska, but gold is also known to occur
in
a few other shoreline locations of States bordering the Pacific Ocean.
Special techniques have been developed to utilize the action of the
surf
in recovering gold from these deposits.

Surf washers are
similar to long
toms, but wider and shorter. They can be used only when the surf is of
proper height. They are set so the incoming surf rushes up the sluice,
washes material from the screen box or hopper, and retreating, carries
it over the riffles and plates. One man can attend to two surf washers,
and about 8 cubic metres can be handled per 10 hours.

An example of a
simple surf washer
is a riffled sluice 1 to 1.25 metres wide and 2.5 to 3 metres long, set
on the sand at the water's edge so that the incoming waves wash through
it to the upper end, and retreat below the lower end. The sluice is
made
of boards nailed to sills at either end which can be weighed down with
rocks or otherwise. The sides are 6 to 10cm high. The riffles in the
example
are made in sections of about 2.5- by 2.5cm strips spaced about 2.5cm
apart.
The end sections are transverse riffles, the center section
longitudinal.
The box preferably is set on a grade of 10 to 15 cm per 4 metres. Best
results are obtained by using mercury in the riffles. When the surf is
strong, the washer treats as much as two men can shovel, but at other
times
it has to be fed very slowly.

In recent years
skindiving enthusiasts
have taken up small-scale placering as both a hobby and a sometimes,
though
seldom, profitable venture.

Various kinds of
apparel and equipment
are used, but the investment is usually not great. Wet suits and canvas
shoes are almost a necessity for entering cold mountain streams to
search
the streambed for pockets that might contain gold. Beginners should be
equipped with a snorkel, a face mask, gloves, a weighted belt, fins, a
gold pan, and a crevicing tool. More experienced divers may use the
popular
scuba equipment, but this calls for special knowledge to insure safety.
Crevicing tools include large spoons, tire irons, crowbars,
etc.--almost
anything that can reach into tight places and dislodge nuggets from the
stream bottom. The pan should be used to test sands from various places
where gold would be expected to settle, such as the downstream sides of
obstructions. Where colors in the pan indicate a favorable area of the
stream, a more intense search may be made.

Mining equipment may
include various
combinations of pumps, miniature dredges, and riffle boxes that can be
built from salvage by the operator or purchased from commercial
sources.
A number of manufacturers have produced special equipment for the
purpose.
One of the popular kinds is the jet dredge, a pipelike device made of
sheet
metal curved at the intake end and with a water jet entry to propel the
water and gravel through the straight portion. The jet is supplied from
a portable pump and in effect causes gravel and sand to be sucked into
and through the pipe. A riffle box built into the end section collects
the gold and other heavy particles while the rest of the material
discharges.
The riffle box may be enclosed so it can function while submerged.
Usually,
a 6- to 10-horsepower pump is adequate; the hose to the jet may be
3-5cm
in diameter.

Manipulating the
device underwater
requires skill and patience, since the riffle section must be kept
nearly
horizontal during the mining operation. Floating platforms are
sometimes
used to support equipment. In this case, riffle boxes and other units
may
be installed on the platform. The usual operation includes moving many
large boulders to get at the trapped gold under neath or alongside.
Conventional
equipment such as a rocker or a sluice may be employed to carry
selected
material from the streambed to a shoreline site for processing.
Concentrates
are then panned to recover the gold.

Problems
You Should Anticipate In Placer Mining

Besides the many
problems already
discussed, such as where and how to find a placer deposit, how to
locate
a claim, and how to sample and mine, a few special operational problems
should be considered. These relate to the physical nature of placer
materials
and the climatic conditions under which they may be found.

Streams with steep gradients
often have
poorly sorted sands and gravels, meaning a wide range of size will be
encountered,
up to cobbles and large, irregularly shaped boulders. Other debris and
tree roots may be present too. Materials that have lain in place for
long
periods become indurated (that is, bound up tightly with clay, or
cemented
sometimes almost to the point of being solid rock), which makes them
exceedingly
difficult to break up with water. Irregularities in the rock surface
underlying
placer materials become important in mining because this is the zone
where
the richest values usually are found. A very uneven surface can be
particularly
difficult to work on. In addition, there is difficulty in Alaska where
ground may be frozen a large part of the year. It may be impractical
for
the weekend or vacation prospector to tackle placers where such adverse
conditions prevail. How these problems are normally dealt with in
larger
operations is discussed briefly under the headings to follow.

Handling Boulders

Boulders are best
left in place
if it is at all possible to work around them. Sometimes, particularly
in
sluicing, it becomes necessary to move the boulders out of the way. A
derrick
operated by a hand winch or steam, gasoline, or electric power may be
used
for this purpose. Possibly several suchderricks will be needed if many
boulders are present. Boulders may be drilled with a jackhammer and
blasted
using dynamite, or more simply blasted with an explosive plastered onto
the rock, a technique called "mudcapping." Platform skips may be swung
from a derrick boom or cableway; the larger rocks are then pried out
and
rolled into the skip for removal. A small bucket-loader vehicle may be
useful for handling boulders, provided it can operate over the type of
surface exposed on the pit floor. Sections of the pit where bedrock has
been cleaned up may be reserved for stacking large rocks. Future
operations
should be planned so repeated handling is avoided.

Trouble With Clays and Cemented
Gravels

Clays and cemented
gravels usually
require the cutting force of the hydraulic giant for effective mining.
In some nonfloating washing plants the gravel is delivered to the head
of the sluice where a giant is used to break up the clay. Indurated or
clayey materials are normally dredged with little difficulty, but if
gravels
are tightly cemented, they may best be mined by shaft or drift methods
using explosives and timbering as required. This presumes they are rich
enough to stand the high cost of such mining and are not exposed enough
for open pit mining. Clay lumps must be broken up quite thoroughly
before
passing through gold-recovery equipment because of their capacity to
imbed
gold particles and carry the gold out with the discharge. The breaking
of clays can be accomplished using the puddling box (previously
described
on p. 29) or with a trommel, which quickly reduces the lumps by its
rotation
and abrading action. Exposure of clays to air is also effective in
breaking
them down, although the time required may be a matter of days or weeks.

Cleaning Bedrock

Cleanup of the last
remaining
materials from bedrock is an important step in gold placering, and if
the
surface is soft, fractured, or uneven, this can be a painstaking chore.
Where bedrock is soft and fractured, gold particles can be embedded as
much as acouple of metres, so it often is advisable to also excavate
this
kind of bedrock material for its gold content. Usually, it is best to
clean
the bedrock as the work progresses upstream. A final cleaning of the
surface
may be left until the end of the season, when there is more time to
spend
on this activity and when the water is short for other work.

Where bedrock is hard
it must
be cleaned largely by hand, and the soft seams and cracks invariably
present
should be cleaned out with hand tools. A hose and small pump are almost
necessities for a good cleanup. Sometimes a separate sluicebox smaller
than that used in the main operation will be employed for handling
materials
from a cleanup operation.

Recovering Your Gold And
Selling It

As you reach the
final stage in
turning arduous labours into a product, the gold should be in either of
two forms--a nearly pure concentrate or an amalgam with
mercury--depending
upon whether the latter was used to implement the collection of gold.
Placer
gold in its natural form is almost always alloyed with a certain amount
of silver, which decreases its fineness. The silver, being much lower
in
value or price per ounce, lowers the value of the gold by a
corresponding
amount. Fineness is based on a scale of 0 to 1,000. As an example, gold
750 fine would be three-fourths gold and probably close to one-fourth
silver.
The important thing is that the gold until it is refined will be worth
somewhat less than the market price for pure gold. The exception to
this,
of course, is specimen material that may have special value in its
natural
form.

Gold in an amalgam
can be heated
or retorted to drive off the mercury, leaving a gold sponge. Great care
should be taken when this is done to avoid inhalation of the mercury
fumes,
which are highly toxic and which can cause a variety of ailments or
even
death. Small quantities of amalgam may be heated on an iron surface,
such
as a shovel face, out-of-doors where the vapors will be quickly
dispersed.
Preferably, a retort is used for environmental reasons and personal
safety.
Mercury, which partially vaporizes at ordinary room temperatures, will
vaporize completely at about 675 degrees F, so an ordinary fire or
propane
burner will suffice. Small retorts are commercially available, or they
can be constructed out of a small cast iron pot with a tight-fitting
cover
to which a short length of water-jacketed condenser pipe is connected.

A typical setup may
have a sloping
pipe 0.5 to 1.4 metres long encased in a larger diameter pipe through
which
water is circulated. A coating of chalk or clay inside the pot will
prevent
the gold from adhering to the iron. The pot is heated gently at first,
raising the temperature gradually until mercury stops coming from the
condenser
outlet. Mercury thus recovered is ready to reuse for amalgamation, and
the spongy mass of gold can be sold. Because amalgams are difficult to
sell, it is usually best to retort your own and market the gold.

Gold is priced and
sold by the
troy ounce, which should not be confused with the better known
avoirdupois
ounce. A troy pound consists of 12 troy ounces and is equivalent to
0.8229
pound avoirdupois. A button of gold that weighed 1 pound avoirdupois
would
contain about 14.6 troy ounces. Normally, gold is weighed on special
troy
scales so the confusion in this odd conversion is eliminated.

The Palmer River Gold Fields

The Palmer River
goldfield was
first gazetted on 27 November 1873. The main mining centers were in
Maytown,
Palmerville and Jessops Hill with the goldfield totalling an area close
on 9000km square.

The Palmer and all of its
tributaries
were worked from the junction of Campbell creek (65km north of Maytown)
to Strathleven. The most productive region was between Byerstown and
Fish
Creek Junction.

Some of the creeks and gullies
worked
were Jessop's, Sandy, Cradle and Oakey Creek. Locations such as
Revolver
Point, Milkmans flat, McGann's and White Horse all yielded plentiful
gold.

With a large
population of Chinese
diggers it was hard to tell what the total gold removed was, as the
Chinese
often sent their winnings home in burial jars. At the time, gold prices
in Australia were around 3p 17s an ounce and the same gold in Hong Kong
went for around 5 pound per ounce. The total estimated return was
somewhere
around about 1,333,893 ozs. of gold.

A good place to start
looking
would be in Maytown as every creek and gully for a radius of 10km
yielded
gold . Overall the soil cover averages a depth of 30cm which means that
most detectors could easily find any nuggets left behind by the old
timers.